DE-NOVO DUPLICATION XQ23-]XQ26 OF PATERNAL ORIGIN IN A GIRL WITH A MILDLY AFFECTED PHENOTYPE

We report a de novo dup(X)(q23-->q26) in a S-year-old girl with growth retardation, developmental delay, and minor anomalies, X-inactivation in lymphocytes by BRDU labeling showed the abnormal X was late replic ating, The androgen receptor assay (HAR) demonstrated a skewed methyla tion (88.8%) of the paternal allele and a 11.2% methylation of the mat ernal allele. These data, which suggest the duplication was paternally inherited, are the first parental-origin identification of a duplicat ion Xq, The mild phenotype of the patient may be related to the size a nd region of the duplication, the low percentage of a dup(X) active de tected by the HAR assay, or a combination of these mechanisms, Am. J. Med. Genet. 70:404-408, 1997. (C) 1997 Wiley-Liss, Inc.